carbidopa + levodopa at a glance
Medicine class
Levodopa with a peripheral dopa-decarboxylase inhibitor
Usual role
Improves motor symptoms of Parkinson’s disease but does not cure it
Timing
Parkinson’s medicines are time-critical and should be taken at the prescribed times
Food
Heavy or protein-rich meals may reduce levodopa absorption in some people
What is carbidopa + levodopa used for?
Selected UK products are licensed for Parkinsonian conditions.
Immediate-release tablets: Parkinson’s disease and Parkinsonian syndrome.
Prolonged-release tablets: idiopathic Parkinson’s disease, particularly to reduce “off” periods in people previously treated with levodopa who experience motor fluctuations.
How does carbidopa + levodopa work?
Levodopa enters the brain and is converted to dopamine, supporting movement signalling. Carbidopa reduces levodopa breakdown outside the brain, allowing more to reach the brain and reducing peripheral adverse effects.
carbidopa + levodopa preparations and strengths
Tablet
Route: Oral
Strengths: 10 mg + 100 mg, 12.5 mg + 50 mg, 25 mg + 100 mg, 25 mg + 250 mg
How to take carbidopa + levodopa
Take it exactly as labelled and do not change or stop treatment without specialist advice.
Swallow prolonged-release tablets whole. Do not chew, crush or halve them.
Do not delay a dose simply to fit around food. Take it consistently in relation to meals.
Heavy or protein-rich meals can reduce the effect in some people. Discuss troublesome food-related fluctuations with the Parkinson’s team.
Seek prompt advice if swallowing becomes difficult; formulation changes require specialist input.
carbidopa + levodopa side effects
Common or expected effects
- Involuntary movements or dyskinesia
- Nausea or vomiting
- Dizziness, including on standing
- Sleepiness
- Hallucinations or confusion
- Dry mouth
Get urgent medical advice
- Allergic swelling, rash or breathing difficulty
- Chest pain, irregular heartbeat or fainting
- Gastrointestinal bleeding
- Severe muscle stiffness, fever and mental change
- Severe depression, suicidal thoughts, delusions or marked behavioural change
- Sudden sleep episodes, especially during driving or hazardous activities
carbidopa + levodopa in pregnancy
Human evidence is limited. Selected prolonged-release products should not be used during pregnancy, while immediate-release treatment requires careful assessment of potential benefit against fetal risk. Contact the Parkinson’s specialist promptly if pregnant or planning pregnancy, and do not stop treatment suddenly.
carbidopa + levodopa while breastfeeding
Levodopa has been detected in human milk, and information about carbidopa is limited. Selected prolonged-release products should not be used while breastfeeding. With immediate-release treatment, a specialist must decide between breastfeeding and treatment, considering its importance to the mother.
carbidopa + levodopa interactions
Check prescribed, over-the-counter and complementary medicines with a pharmacist or prescriber.
Non-selective monoamine oxidase inhibitors
Must not be combined because of potentially serious reactions; any washout must be specialist-managed.
Iron salts
Ferrous sulphate and ferrous gluconate can reduce carbidopa or levodopa availability and may reduce symptom control.
Antihypertensives
May worsen postural hypotension, requiring blood-pressure review.
Common questions about carbidopa + levodopa
Answers are fully visible for fast scanning and source review.
Is carbidopa + levodopa the same as co-careldopa?
Yes. Co-careldopa is the UK-approved name for this combination.
Does it cure Parkinson’s disease?
No. It improves symptoms while being taken but does not stop the underlying condition progressing.
Can it be taken with food?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.